The short answer
Production changes with season, weather and shade, so compare like with like: this month against the same month last year, or against a location-based estimate. DOE’s federal O&M guidance notes that PV performance varies with location, daily weather and severe weather events. If production is clearly lower than last year in similar weather, and there are no alerts, shade or snow to explain it, it is worth a closer look.
Safe checks you can do now
- Pick the right baseline
Compare this month with the same month last year in your monitoring app, not with your best summer day. If the system is new, use your proposal’s monthly estimate or a location-based estimate such as PVWatts calculator: location-based production estimates.
- Check the app for alerts
Look for error, offline or not-reporting alerts. Missing data can look like low production.
- Look for shade from the ground
Trees grow. Compare the array with photos from when it was installed. New shade in the morning or afternoon can cut output on part of the array.
- Look for dirt, leaves, pollen or snow
From the ground, check for heavy soiling, leaves, bird droppings or lingering snow. Do not climb onto the roof or spray panels while standing on a ladder.
- Check your breakers without opening anything
If production dropped to zero, check whether a breaker labelled for solar has tripped. If it trips again, stop and call a licensed electrician.
- Get a second set of eyes on the data
If none of these explain it, share access with your installer or request our free remote review.
Only do the checks on this page that need no tools: read the app, look at the inverter or gateway lights, reset a tripped breaker that is labelled for the solar system or gateway, and look at the array from the ground. Never open an electrical panel, inverter, combiner or junction box, never touch wiring or connectors, and never climb onto the roof. Solar equipment can stay energized while the sun is up even when the grid is off. If a breaker trips again, you smell burning, or you see scorch marks, water in equipment or damaged wiring, stop and call your installer or a licensed electrician.
What remote data can and cannot tell you
Monitoring data can show when production changed, whether one inverter or panel fell behind the others, and whether the change matches weather. It cannot see a cracked panel, a loose connector or a new branch over the array. That is why some issues need an on-site visit or your installer even after a careful remote review. Try our solar underperformance check for a quick first comparison.
When to call your installer or an electrician
- Production is well below the same month last year in similar weather.
- One inverter, string or panel consistently produces less than its neighbours.
- An alert does not clear.
- You notice damage, loose wiring or a breaker that trips again.
If you are not sure, treat it as a job for a professional. Our free remote review can help you decide what to ask for, but it does not replace a licensed electrician or your installer.
Get a free remote review of your system
Tell us which monitoring app your system uses (Enphase, SolarEdge, Tesla, SMA, Fronius, Generac or another brand). We send you the steps to add our team as a viewer or installer from inside the provider’s own app. You never share your password with us. Once access is granted, our team connects your system and runs a free remote review of your production and alerts, then tells you what we found and the next step.
- 01Tell us your monitoring brand
- 02Grant viewer or installer access in your app
- 03Our team reviews it and reports back
Remote data can show when and where production changed, but it cannot always find the physical cause. Some issues need an on-site visit or your installer. We never ask for your monitoring password.
Prefer not to use the form? Start your free review here.
Questions homeowners ask
How do I know if my solar panels are underperforming?
Compare the same month across years, or compare against a location-based estimate for your system. A clear shortfall in similar weather, with no shade, snow or reporting gap to explain it, is a sign to investigate.
Can dirty solar panels reduce production?
Yes. Tesla, for example, lists extended periods of accumulated dust, snow or debris as factors that may reduce total energy production. Check from the ground and ask a professional before any roof work.
What production should my system make?
Your installer’s proposal should include an estimate. Tools such as PVWatts give location-based monthly estimates for a given system size, tilt and orientation.
Related guides
Sources
- U.S. DOE (FEMP): Operate and maintain an existing PV system
- PVWatts calculator: location-based production estimates
- Tesla Support: Understanding system performance
- U.S. DOE: Homeowner's guide to going solar
Brand-specific facts and error-code meanings come from the manufacturer’s own documentation, linked above, checked 2026-10-09. Manufacturers update their guidance; follow the current version for your equipment. Published by Solar Survey AI. Our safe-action advice is our own, not the manufacturer’s.